一种测量镇静大鼠气道反应性的非侵入式新方法

A NEW NON-INVASIVE METHOD FOR MEASUREMENT OF AIRWAY RESPONSIVENESS IN SEDATED RATS

将腹腔注射地西洋（7．5mg／kg）而镇静的SD大鼠，置于体积描记器，测定其自主呼吸变化。吸入氯化乙酰甲胆碱（MCh）和氯化乙酰胆碱（ACh）气雾对呼吸幅度无明显影响，可浓度依赖性地增加呼吸频率，且两药的作用强度相似，但MCh作用维持11min，ACh仅维持3min。乌拉坦麻醉可抑制呼吸和对MCh的反应；硫酸阿托品、硫酸沙丁腹醇和氨茶碱抑制MCh引起的频率增快：吸入抗原气雾后6h能增强致敏大鼠对MCh的敏感性。实验表明，按本方法用地西泮镇静和吸入MCh是测定大鼠气道反应性的理想条件，呼吸频率增快可作为气道反应性的指标。

Sprague-Dawley rats sedated with intraperitoneal injection of diazepam (7. 5 mg/kg) were placed in a plethysmograph to measure the changes in spontaneous respiration. Inhalation of methacholine (MCh) or acetylcholine (ACh) aerosol did not alterthe volume of breathing, but increased respiratory frequency (RF) to the same extentin a concentration-dependent manner. On the other hand, the tachypnea effect of MChlasted 11 min, and that of ACh only 3 min. Urethane anesthesia inhibited spontaneousrespiration and the response to MCh. Atropine, salbutamol and aminophylline inhibitedMCh-induced tachypnea. In sensitized rats, the response to MCh was potentiated 6 h afte r inhalation of ovalbumin aerosol. The results indicate that sedation with diazepamand inhalation of MCh aerosol used in this report are suitable for measuring airway responsiveness in terms of degree of increase of respiratory frequency.